ok - maybe what i am about to tell you is pretty normal so i apologize about posting it. also, if it is, could you explain it to me why it's happening and how it works. so, i got a domain name mykeyword.com and build a site because many people search for "my key word" on google. now when i search in google for the phrase "my key word" i don't see my site on the first page but when i search for the phrase "mykeyword" it's listed as the first site. nowhere on my site do i have the phrase written as one word. so, my conclusion is that google sees my domain name as one word. what would happen if i would buy my-key-word.com and build a site? would google still see this as one phrase or would i have more luck when people search for "my key word"? i hope you understand what i'm trying to say. thanks in advanced for your help!
mykeyword.com and my-key-word.com have a pretty equal chance of ranking for "my key word" and in general it's much easier to tank an exact domain match, though this needn't happen automatically or immediately. Such a match gives you a head start though it is not decisive if the keyword is competitive.